1. Field of the Invention
The present invention relates to a herbal medicinal composition, an extract thereof, and a method for manufacturing the same and, more particularly, to a herbal medicinal composition and an extract thereof for inducing proliferation of cranial nerve cells and a method for manufacturing the same.
2. Description of Related Art
In developed countries, cerebrovascular diseases are one of the ten leading causes of death and even survivors suffer critically with disabled limbs. Therefore, medical treatment and care for both acute and chronic cerebrovascular diseases have already become burdens of society and countries. Stroke is one of cerebrovascular diseases and generally happens in aged people. As the structure of the population tends to advanced age, the incidence of stroke rapidly increases.
The common stroke is classified into ischemia-type stroke and hemorrhage-type stroke. The ratio of the ischemia-type stroke is about 80% and that of the hemorrhage-type stroke is about 20%. Since strokes strike very suddenly, irreversible lesions in the brain of a patient and even death will occur if the patient is not delivered to a hospital for immediate treatment. Therefore, if treatment can be applied to a patient suffering a stroke within an efficacious period to prevent irreversible lesion in his/her brain, death and disablement rates can be decreased so as to reduce difficulty for rehabilitation after healing and further to advance the quality of life of the patient.
Currently, anti-thrombotic therapy and anti-coagulation therapy are used for the prophylaxis and treatment for ischemia-type stroke. The anti-thrombotic therapy generally used for strokes resulted from brain infarction can prevent strokes from being more severe and restrict thrombi in the artery so as to avoid spread of the thrombi to other regions. Besides, clinical reports show that anti-coagulation therapy may cause undesired bleeding in the region injured by strokes in many patients, and thus the anti-coagulation therapy is used in a reduced rate manner. Furthermore, for the treatment of ischemia-type stroke, the important things are active elimination of acute causes inducing stroke, reflow and perfusion of blood in brain vessels (for example, utilizing thrombolytic agents in veins or arteries) as quickly as possible, and the reduction of death of brain cells by neuron protective agents.
However, the brain cells' tolerance of ischemia is very poor and thus lesions of neurons generally become irreversible before the patients are delivered to hospital for treatment. Accordingly, it is extremely important to increase tolerance of blood and oxygen deficiency and to alleviate injuries of blood and oxygen deficiency to brain neurons.
It has been known for a long time that the central nervous system does not have a characteristic of self-regeneration. In detail, neural stem cells are not contained in the neurons of the central nervous system of adult mammals and thus the neurons do not regenerate after exposure to diseases or injuries. However, research has evidenced that neural stem cells exist in the central nervous system currently. These neural stem cells can be isolated from different regions of hippocampus, ependyma, and so forth. Hence, it is evidenced that neural stem cells exist in the brain of adult mammals and they have the following characteristics of abundant proliferation in vitro and differentiation into neurons and glia cells.
Although functions of the neurons and glia cells in situ regenerated from the neural stem cells are still not clarified, the neural stem cells have potential to be used for treatment of chronic stroke, neurodegeneration, and so forth because of their pluripotency. However, no efficacious medicines can activate differentiation of neural stem cells into neurons and glia cells to replenish brain cells in injured regions at present. Therefore, there is an urgent need to find safe and efficacious medicines or methods for treating strokes.